Electromagnetic vibratory motor



July 4, 1939. E. l.. BARRETT ELECTROMAGNETIC VIBRATORY MOTOR Filed June 25, 1954 fZUefiZJfv Edward L affe A In u.

Patented July 4, 1939 UNITED STATES PATENT OFFICE Utah Radio Products Company,

Chicago, Ill.,

a corporation of Illinois Application June 25, 1934, Serial No. 732,234

7 Claims.

The invention relates generally to electromagnetic vibratory motors and more particularly has reference to a device which is especially well adapted for use in connection with systems for converting direct current of low potential into direct current of high potential, such, for example, as B battery eliminator systems which are primarily intended for use in automobile installations of radio receiving sets. y

Heretcfore in vibratory motors intended for this type of work, unusual diiculty has been encountered in obtaining a proper adjustment of the cooperating parts and especially o'f the several separable contacts. In manufacturing. such devices, it has been necessary to adjust the parts by hand several times during assembly, which, since the clearances involved are measured in a few thousandths of an inch, requires considerable time and skill on the part of the workman, thus materially zo increasing the cost. Moreover, it has been found that in operation the vibratory contact member or reed of previous devices has a tendency to shift out of its original assembled position, thus disturbing the accurate adjustments and resulting in the failure of the device.

It has been customary to support the vibratory reed by a frame through the medium of what is known as a stack and which consists of a large number of layers of thin pieces of insulation and so interposed strips of metal for contact purposes. I have discovered that the primary source of trouble in previous devices is the stack. Thus, if the elements of the stack are slightly loose when assembled, the constant vibration of the reed in operation will in time cause the reed to shift its position and even the slightest shift may disturb the adjustments to such an extent that the device becomes inoperative. Or, if the elements of the stack are slightly warped, uneven in thickness, or q) otherwise irregular, the parts cannot be assembled with any assurance that the operation thereof will be satisfactory for the expected life of the device nor with any degree of uniformity. Obviously if the devices are not alike after assembly, each device must be separately adjusted at an increased expense. These same disadvantages are present when the contacts with which the vibratory reed cooperates are supported from the stack with the increased possibility of some part shifting to destroy the adjustment.

An object of the present invention is to provide an electromagnetic vibratory motor which is simple in construction, in which the component elements may be assembled with such accuracy as to require only a nal adjustment, and in which the number of parts and the overall dimensions of the device are reduced to a minimum.

Another object of the invention is to provide a device of this character which includes a supporting frame and a vibratory element which are 5 directly connected together Without the use of any intermediate part whatsoever.

More specifically stated, another object of the invention resides in the provision of a vibratory motor which embodies a single member bent to 10 form a frame structure having opposed parts upon which stationary contacts are iixedly mounted and between the ends of which a vibratory member is directly secured in such manner that the relationship of the vibratory reed to the assembly and to the xed contacts is unvariable after assembly whereby contacts which are carried by the vibratory member may be permanently adjusted with respect to the xed contacts as the nal step of assembling the device.

Other objects and advantages will become apparent in the following description and from the accompanying drawing, in which:

Figure 1 is a longitudinal central section through a device embodying the features of the present invention.

Fig. 2 is a similar sectional View taken at right angles to the section shown in Fig. 1.

Fig. 3 is a greatly enlarged fragmentary sectional vieW showing the details of the mounting of the vibratory member and the several contacts. and is taken along the line 3-3 of Fig. 2.

Fig. 4 is a similarly enlarged transverse section lthrough the device taken along the line 4--4 of Fig. 2 and looking in the direction of the arrows.

While the invention is susceptible of various modifications and alternative constructions, I have shown in the drawing and will herein describe in detail the preferred embodiment, but it is to be understood that I do not thereby intend to limit the invention to the specific form disclosed, but intend to cover all modications and alternative constructions falling within the spirit and scope of the invention as expressed in the appended claims.

The vibratory motor, which has been shown in the drawing as illustrative of a device embodying the present invention, is of the type especially adapted for use in a system wherein direct current is mechanically interrupted to produce a transformed alternating current of higher potential which is then mechanically rectified to produce a direct current cf high potential.` With only minor changes, the present device can be used as well in systems wherein the alternating current of high potential is r'cued by means of a valve.

Referring to the drawing, Il! designates generally an electromagnetic vibratory motor which is housed within an enclosing container I I The motor I embodies a frame I2, which, while it may be formed of several pieces,.is preferably fashioned from an elongated strip of relatively heavy metal stock which if desired, may be of magnetically permeable metal, such as steel. Said strip is bent into an elongated, generally rectangular, or box-like structure having side walls I3, a closed end I4, and a split base I5`where the opposite ends of the strip are brought together. The extreme ends I6 of the strip are turned outwardly, as shown, to provide opposed meeting faces II of substantial size located approximately on the central longitudinal plane of the frame. In so far as it is possible, the meeting surfaces I I are perfectly flat and parallel to said central 'plane of the frame.

' The closed end I4 of the frame carries a small electromagnetic winding I 8 which is permanently aiiixed thereto in any suitable manner at one side of the longitudinal plane on which the flat surfaces I'I are located. A preferred and simplified means for mounting the electromagnet on the frame is best seen in Fig. 2. The winding I8 is of the spool type and encircles a core I9 formed of a thin rectangularly shaped piece of magnetic iron. The winding I8 is supported upon a spool element 20 which fits closely about the core with the ends of the spool resting in recesses formed in the core. The margins of the core adjacent to said recesses are upset, as indicated at 2l, to secure the core and winding permanently together.v

One end of the core, indicated at 22, is extended beyond the adjacent face of the spool element and is arranged to be received snugly in an appropriately dimensioned slot 23 formed in the closed end I4 of the frame. The core end 22 is preferably of reduced width to provide shoulders 24 for determining the proper position of the core and winding relative to the frame end. The electromagnetic winding structure may be secured to the frame in any suitable manner as by upsetting portions of the core end 22 or by soldering the parts together.

Avibratory member 25 in the form of an elonl gated reed of spring steel is mounted on the frame -by interposing one end 26 thereof directly between the ends I6 of the frame and in 'abutting engagement with both of the plane surfaces II. Preferably, as shown in Fig. 2, the frame surfaces I'I have both faces thereof knurled or otherwise provided with av plurality of crisscross lines to produce perfectly plane surfaces. Screws 21 or the like secure the`frame ends I6 and the reed end 26 rigidly together. Washers 28'may be used to insure tightness and, since the parts are electrically connected, a contact 29 may be interposed between one of the washers and the adjacent frame end.

Thus, the reed may be permanently and securely mounted on the frame. The frame end I6, by an ordinary stamping process, can be so fashioned that the surfaces I'I thereon are perfectly plane within very 4close limits of tolerance. The reed end 26, being practically a plane surface, will fit accurately between the'surfaces I1 and the assembly is completed by merely seating the screws 21 tightly. Hence 'n o errors or inaccuracies of part relationships are introduced in the present assembly as is too frequently the case when the reed is supported from the frame mein-I bers by an interposed stack of laminations.

When the reed is assembled, it will extend between the frame sides I3 substantially on a parallel medial plane and the reed is so dimensioned as to reach nearly to the adjacent exposed face of the electromagnet core I9. This end of the reed carries a small armature 30 and it is preferred that the reed contacting face of the amature be knurled as in the case of the surfaces I'I to avoid reed distortion. Since the electromagnet is located at one side of the center plane,

the armature by this construction is located at one side or eccentrically of the center of magnetic force exerted by the electromagnet. Where the frame I2 is fashioned of magnetically nonpermeable metal,`the effective magnetic force results from magnetic flux leakage around the electromagnet. If the frame is of steel a substantially closed magnetic path is provided which includes the electromagnet core, the frame, and the reed. However, due to the reluctance of the thin reed, the ux leakage is still effective as a force to which the armature reed responds. Consequently, either magnetically permeable or nonpermeable metal may be used in the frame without materially affecting the efficiency of the device.

The frame sides I3 carry fixed contacts generally designated at 3| andthese contacts are preferably located about half way along the free' portion of the reed. Since the illustrated device is primarily intended to be used in a system wherein alternating current rectification is accomplished mechanically, four contacts are employed, two of which serve to effect an alternate interruption of a direct current circuit to the primary winding of a transformer, while the other two contacts alternately establish a rectifying connection between the transformer secondary and load. 'I'he contacts are mounted in transversely alined pairs on the frame sides I3 and, since the manner of moimting the contacts is the same, only one need be described.

Each contact comprises an elongated stud 32 having a head 33 which is faced with a layer 34 of a suitable contact material. The stud and head are preferably formed of a relatively soft current conducting material. The stud 32 extends through an insulation bushing 35 which is snugl@ ly seated in an aperture 36 formed in the frame side I3, the head 33 and contact 34 being located f on the inner side of the frame. Mounted on thc stud 32 next to the head 33 is a washer 31 of substantially greater diameter than that of the ap erture 36 and between the washer and the frame side I3 is a still larger washer 38 of suitable insulation such as mica. Similarly, on the outer side of the frame is an insulation washer 39 and a smaller washer 40 having a lateral extension 4I for connection with a lead 42. The parts preferably are secured in place by upsetting the outer end of the stud 32 as indicated at 43. The larger dimensions of the washers 31, 38, 39 and 4U are important in order that the contact will vbe permanently and immovably secured to the frame.

arms 45 which, as shown in Figs. 2 and 3, extend 75 in outwardly offset pairs from common bases 46 which in turn are secured as by rivets 41 to the vibratory reed 25. Preferably the reed contacting faces of the bases are also knul-led to avoid distortion of the reed. The point of connection between the bases 46 and the reed is between the xed contacts and the xed end of the reed, and the contact arms 45 extend in overlying relation to the contact faces 34 where the contact fingers carry contacts 48 for cooperation with the fixed contact faces 34.

In operation, as the reed 25 vibrates, the pairs of contacts thereon will be moved into alternate engagement with the fixed contacts on the opposite frame sides.

The present construction has greatly simplified the assembly and adjustment of the parts. Thus, in assembly the fixed contacts 3| are preferably mounted on the frame before the vibratory reed is assembled thereon. The frame with the fixed contacts properly secured thereto may be placed in a .suitable jig or fixture wherein the proper spacing of the opposed fixed contacts can be effected by bending or offsetting the frame sides, as shown in Fig. 1. Likewise the movable contacts 44 may be afxed to the reed before the reed is mounted on the frame and the reed may then be placed in a suitable jig or fixture for adjustment of the spacing of the movable contacts, this adjustment being obtained by bending the fingers 45. The separately adjusted reed and frame are then assembled and it has frequently been, found on final check that the unit requires no further adjustment. At worst, only a minute adjustment is all that is ever necessary.

'I'hus the disadvantages resulting from inaccuracies in a frame, reed and stack construction or from differences in the thickness of the stack, or from the insecurity of the reed due to looseness inthe stack, all or any of which will impair or destroy the accuracy of adjustment, are entirely eliminated in the present construction.

The inherent disadvantages resulting from the vibrations of a motor of this character are minimized in the present instance by a special form of enclosing casing. The motor, as shown in Figs. 1 and 2, is mounted in a container having an outer closed case comprising a can-like metal shell 49 and a tightly tting cover 5|) which are permanently secured together in any suitable manner, as by spots of solder 5I. The end or base of the cover is centrally apertured and is closed by a'n insulation plate 52 to which a plurality of projecting prongs 53 are secured. The inner surface of the shell 49 is lined throughout with a layer 54 of felt or similar noise and vibration absorbing material, while an enlarged plug 55 preferably fashioned of sponge rubber is seated in the cover and within the open end of the case. The leads to the\motor extend through passageways in the plug 55 for electrical connection with the several prongs.

The plug 55 within the shell is peripherally recessed, as at 56, and an inner metal shell 51 is eration of the device.

the connection between the prongs and a complementary socket cannot work loose during the op- It'is to be noted that the inner shell 51 is ungrounded whereby electrical interference due to sparking between the points is effectively reduced.

From the foregoing, it will be evident that a novel vibratory motor structure has been provided which is exceedingly simple, may be assembled and adjusted efficiently and accurately, and is noise and vibration proof. The simplified construction is sturdy. The necessary adjustments may be speedily obtained with an unusual degree of uniformity and such adjustments are permanent. The present device embodies few parts which are so related that an unusually small and compact unit may be produced. In Figs. 1 and 2 the dimensions shown are substantially full scale.

I claim as my invention:

1. A vibratory motor comprising, in combination, a rigid frame divided to provide opposed flat faces located substantially on a central longitudinal plane of the frame, a vibratory member interposed and clamped directly between said faces in abutment with both, means for rigidly securing the parts 'in such relationship, and means for effecting vibration of said member.

2. In a vibratory motor, the combination of a frame having opposed parts adapted to be brought close together, and a vibratory reed rigidly secured in directly interposed relation between said parts and in contact therewith.

3. In a vibratory motor, the combination of a frame formed of a continuous piece of material bent into box-like shape and having the opposite ends thereof turned to provide opposed faces of substantial size, and a vibratory reed having a portion thereof clamped between said faces and in direct face-to-face contact therewith, and with the remainder of the reed projecting away from said faces for free vibration unobstructed by said frame.

4. In a vibratory motor, the combination of a frame formed of a continuous piece of material bent into box-like shape and having the opposite ends thereof turned inwardly to provide opposed faces of substantial size adapted to meet substantially on a central longitudinal plane of said frame, and a vibratory reed secured between said faces in direct face-to-face contact therewith to extend inside said frame substantially on said central plane.

5. In a vibratory motor, the combination of a frame formed of a continuous piece of material bent into an elongated rectangular frame and having the opposite ends thereof turned to provide opposed faces, an electromagnet mounted at the closed end of the frame, and a vibratory reed secured between said faces in direct face-to-face contact therewith and extending to a position for cooperation with said electromagnet.

6. A vibratory motor comprising, in combination, a closed frame divided to provide opposed flat faces located substantially on a central longitudinal plane of the frame, a vibratory reed interposed directly between said faces in abutment with both, means for rigidly securing the parts in such relationship, means for effecting vibration of said reed, xed contacts rigidly mounted on said frame, and cooperating contacts flexibly connected with said reed.

7. A vibrator for use in a B-battery eliminator for an automobile radio receiver or the like comprising, in combination, a rigid and generally 4 aieaeaa elongated frame presenting a laterally disposed face adjacent one end thereof, e, cantilever type vibratory reed adapted to vibrate at a. substantieliy xed frequency determined largely by the resilient characteristics of the reed, said reed being fashioned in the form of an elongated at strip of metal, means for clamping the butt end portion of said reed in direct ace-to-ace contact with said face om said frame and with the remainder of the reed projecting toward the other end of said frame, and a plurality of make and break contacts arranged-to be actuated by said 5 reed in the Vibration thereof.

Y EDWARD L. BARRETT. 

